Resilient bearer for offset presses



Aug. 24, 1948.

.Laszlu M Stamps] INVENTOR enema Au :4, 194a ww aasmsnr Banana sonorrsa'r. masses Lauio u. Stempel, New York. n.1,

mesne assignmentuto R. York, N. Y., a corporation alllgnor, by Hoe k00., Inc.,-New

of New York Application June 18, 1946, Serial No. 876,518

This invention relates to printing machinesand, more particularly tomeans for eliminating vibra' tion of the printing cylinders thereof.

In lithographic offset printing machines the blanket cylinder is coveredwith a transfer surface or blanket, of rubber or simllar'material,attached to the surface of the cylinder. A gap is left in in Figure 1 isillustrated a (Cl. 101-211) Referring more particularly to the drawings,

a blanket roller or cylinder i, comprising" a main body 2 and havingbearer ring 1' formed the surface of the'cylinder at the 'pointsofattachment. During operation of the press, when this 1 gap is oppositethe periphery of theopposing impression cylinder, the difference inpressure created causes vibration of the. press. Similar eifects mayoccur in other types of presses and cause vibration due to interruptionof the surface of a plate or form-cylinder and the consequent variationin pressure between such form cylinder and the impression cylinder.

The general object of thisjinventionistoprovide means for equalizing thepressure during the revolution of the cylindera'thus smoothing out theoperation of the press andpreventing wear and stress caused thereby.

This result is preferably accomplished by the provision of spring-loadedplunge'rs set into the impression cylinder at the point or points wherethe gaps in the surface ,ofthe blanket'cylinder are opposedtotheperiphery of the-impression cylinder, and providing hardened metalrings or bearer surfaces on the ends of the blanket cylinder to beengaged by these plungers. The pressure created by the plungers, bearingagainst the bearer ring surface of the blanket or printing cylinder atthe instant when thegapin the surface of the blanket or printingcylinder opposes the periphery of the impression cylinder, is madesubstantially equal to the normal pressure onthe sheet or web beingprinted, and hence there is no reduction in the pressure between the twocylinders while the gap is passing.

It is also an object of this invention to provide .gap 5 in the surfaceof the blanket or printing at each end thereof, of hardened metal orother suitable material. The

,main body of the-cylinder is covered with a blanket 4, rubber or anyother suitable material, which is-wrapped around the surface of thecylinder body I and fastened thereto in a channel! formed in thecylinder body, in any suitable manner. The blanket or printing cylinderlis supported'on an axle or shaft 6 for rotation therewith. Since theends of each of the cylinders are the same, only one end is shown in thedrawing, and the other machine parts are omitted.

"As will be understood by those skilled in the art, suitable inking andplate cylinders cooperating with the blanket cylinder will be provided.

Cooperating with the above described blanket or printing cylinder l isan impression cylinder l0 having a main body ii and a surface I! formedat each end thereof. The impression cylinder is supported by a shaft i8,which shaft, as well as the shaft 8, is supported in the frame of thepress in any suitable manner, not shown.

--To elimii late the vibration resulting when the cylinder i reaches theimpressionpoint, or in other words, is adjacent the periphery of the a.mechanism for accomplishing the abovedescribed purposes which issimple-in construction and operation and also inexpensive.

with these and other objects in view, as may I appear from theaccompanying specification, the invention consists in the variousfeatures of conll, through which pins struction and combinations ofparts which-will-be" first described in connection with the accompany.-

ing drawings, showing a. resilient-bearer for print ing pressesembodying the invention in a pre- 1 are embedded in or otherwise rigidlyafllxed to' ferred form, and the features forming the invention will bespecifically pointed out in the claims.

In the drawings: p Figure 1 is a side elevation ofone endofa printingcouple embodying the presentiinven tion;

Figure couple shown in Figure 1; and

Figure 3 is a section on the line ofil ikure 1.

2 is an end elevation of the printing passage or bore ends slightlybeyond I plungers impression cylinder Iii, spring-loaded plungers' areinserted into thesurface i2 of the impression cylinder ll, extendingoutwardly therefrom and contacting the surface of the bearer ring orsur- 'face I of the blanket cylinder during rotation of the cylinders.The plungers l3 are so located in the surface I! as to contact 3'. atthe same time as the gap 5 is adjacent the surface of the cylinder ill,creating pressure between the two cylinders to offset the lack ofpressure incident to the passing of the gap in the surface of theblanket cylinder.

The plungers i3. are located in bores it formed in the cylinder It, withtheir outer ends protrudin'g beyond the peripheral surface thereof.Openings it are formed in' the bodies of the plungers i5 extend. Thepins ii are of smaller diameter than the openings I6 and the body of thecylinder ill. The difference in diameter between the openings l6 and thepins ll allows the plungers to reciprocate within the ll sufficiently tobring their outer the periphery of the impression. cylinder. A spring I1is located within the .bore II and bears against the inner ends of theplungers i3, exerting outward pressure thereon.

As the cylinders l and iii rotate, one of the II will contact thesurface of the bearer. ring 8' each time the gap in the surface of theresiliently covered cylinder i comes opposite the the bearer surfaceace-moi surface of the impression cylinder II. the plungers being soarranged and located, according to the sizes of the cooperatingcylinders, as to provide for this. In the drawings the blanket cylinderis shown as one-half the diameter of the impression cylinder, andconsequently only two plungers are illustrated. It is to be understoodhowever than any number of plungers may be employed, as governed by therelative sizes of the cylinders and the number of gaps to be balanced.The bearer surfaces 3' of the blanket cylinder need not be continuous,since it isonly necessary that they be provided at the gap in theblanket cylinder where they will engage the plunger is of the impressioncylinder.

The bearer surfaces and the cooperating plunger or pressure exertingmechanisms have been illustrated as applied, respectively. to theblanket cylinder and the impression cylinder. However, this applicationmay be reversed, if desired, this being governed by the structuralfeatures of the press and the arrangement of the printing cylinder.

In the drawings, the impression cylinder II is shown as having a surface[2 formed thereon. In the preferred embodiment, this surface I! has adiameter slightly less than the diameter of the main part of theimpression cylinder ll, so that the pressure between the two cylinders,l and II, is carried by the surfaces of the main bodies of saidcylinders, or by the paper, at all times except when the gap 5 in thesurface I is adjacent the surface II, at which time the pressure isborne by the plunger is and bearer surface I.

As will now be apparent, the invention provides for bearer surfacesattached to or embodied in one of the cylinders of a printing machinewhich will cooperate with plungers or other resilient pressure exertingdevices associated with the other cylinder of a couple, these pressureexerting devices and cooperating surfaces being so arranged as toprovide additional pressure between the two cooperating rotatingcylinders at all times when the paper and the printing blanket or plateare interrupted, so as to maintain a substantially constant pressure. Inthis way pressure variation and consequent vibration are eliminated orreduced to a minimum. While it is preferred to utilize resilient membersof the type shown and to associate the same with the impressioncylinder, such members may be associated with the plate or blanketcylinders, if preferred, and other means for applying resilient pressurebetween the printing couples may be utilized without departing from theinvention in its broader aspects.

What I claim is:

1. In a printing couple including a cylinder having a gap in the surfacethereof, the combination of rigid concentric bearer means for saidcylinder, and resilient means associated with the other cylinder of saidcouple for exerting radial pressure against said bearer-means over arestricted arc inaxial alignment a 1th the. gap when said gap is at theimpression point.

2. In a printing couple having cooperating impression and printingcylinders, said printing cylinder having a ap in its surface,thecombination of rigid concentric bearer of said cylinders, andresilient means incorpomeans for one over a restricted. arc in axialrated in the other of said cylinders for exerting 1 radial pressureagainst said bearer meansover a restricted arc in axial alignment .withthe gap when said gap is adjacent impression cylinder, wherebysubstantially conthe surface of 'said' able spring-loaded otherv .ofsaid cylinders for exerting pressure- 7 bination of rigid concentricbearers for one of said cylinders, and radially movable spring-loadedplungers incorporated in the other of said cylinders for exertingpressure against said bearers when said gap is adjacent the surface ofsaid impression cylinder.

.4. Ina printing couple having cooperating impression and printingcylinders, said printing cylinder having a gap in its surface, thecombination of rigid concentric bearer means for one of. said cylinders,and resilient means for applying radial pressure against said bearermeans alignment with the gap when said gap is opposite the impressioncylinder whereby substantially constant spacing and pressure between thesaid cylinders is maintained.

i5. In a printing couple including a cylinder having a paper-engagingsurface extending partially around its peripheral surface and leaving agap therein,-the combination of rigid concentric bearers for one of saidcylinders, and resilient means cooperating with said bearersoverarestricted arc in axial alignment with the gal for. exertingadditional pressure between said cylinders when said up reaches theimpression point.

6. In a printingcouple including a cylinder having a paper-engagingsurface-extending D 4- tiaily around its peripheral surface and leavinga gap therein; the combination of rigid concentric bearer means for saidcylinder, and resilient means embodied inthe other cylinder of saidcouple cooperating with said bearer means over a restricted arc in axialalignment with the gap to increase the pressure between said cylinderswhen said gap reaches the impression point.

- 7. In a printing couple having cooperating impression and blanketcylinders, a blanket of rub-= her or similar resilient material coveringthe 'sur-' face of said blanket cylinder, and s, gap in the 8. In aprinting couple having cooperating impression and blanket cylinders, ablanket of rubber or similar resilient material covering the:

surface of said blanket cylinder, and a gap in the surface of saidblanket cylinder at the pointof attachment of said blanket'to saidcylinder,

the combination of rigid concentric bearer sub" faces for. one ofsaidcylinders, and radially movplungers embodied in the against said bearersurfaces when said gap is diacentthe surface 9. In a printing couplecomprising a pair'of cooperating"v rotatable cylinders, an impressionsurface on one-cylinder, aprinting surface onthe other cylinder, thesaid printing surface having .a, gap which periodically passes adjacent.to,the impression cylinder when the cylinders are ro-- tated, and aresiliently supported'member-inlbne of the cylinders arranged to exertpressure in a of said impression cylinder.

radial direction and to engage a bearer surface on the periphery of itscooperating cylin- UNITED STATES PATENTS der during each such passage ofthe gap. i t Name D W LASZLO M. STEMPEL. 421,749 Nagel Feb. 18, 1890 1472,206 Cottrell Apr. 5, 1892 REFERENCES CITED 1,111,490 Wood Feb. 15,1916 2,098,165 Rizgenbach Nov. 5, 1937 The following references are ofrecord in the file of this patent:

